Signal attachment for offshore barge jacks



Nov. 5, 1963 J. ROUSSEL SIGNAL ATTACHMENT FOR OFFSHORE BARGE JACKS 3 Sheets-Sheet 1 Filed Aug. 24, 1960 Lou/L9 J. Rousse/ ZNVENTOR. BY @Mm WW 3 M1 and Nov. 5, 1963 L. J. RoussEL SIGNAL ATTACHMENT FOR OFFSHORE BARGE JACKS 3 Sheets-Sheet 2 Filed Aug. 24, 1960 "w QM NEW W L vwt Nov. 5, 1963 L.- J. ROUSSEL 3,109,289

SIGNAL ATTACHMENT FOR OFFSHORE BARGE JACKS Filed Aug. 24, 1960 3 Sheets-Sheet 3 Lou/Ls J. Rousse/ IN VEN TOR.

United States Patent 3,199,289 SIG NAL ATTACHMENT FOR OFFSHORE BARGE JACKS Louis J. Roussel, New Orleans, La., assignor to Universal Drilling Company, Inc., a corporation of Louisiana Filed Aug. 24, 1960, Ser. No. 51,729 21 Claims. (Cl. 61-465) This invention comprises a novel and useful signal attachment for ofishore barge jacks and more particularly relates to an attachment adapted for use with the hydraulic jack assembly for barge caiss-ons of the type disclosed and claimed in my prior application, Serial No. 60,262, filed September 30, 1960, and which is a continuation-in-part of my prior co-pending application, Serial No. 568,761, filed March 1, 1956, and now abandoned.

In my above-identified prior applications there is disclosed and claimed a caisson and hydraulic jack con- 'struction for barges whereby a barge, preferably of the type suitable for offshort well drilling may be raised above the water level on the caissons by the hydraulic jacks so as to remove the barge from the eifects of waves and thus enable the barge to form a stable drilling platform. While the hydraulic jack and caisson mechanism tunetion satisfactorily for the purpose intended, an opera tional problem arises in the use of such apparatus in the engagement of the power operated locking and gripping jaws of the jack mechanism upon the caissons. Owing to the size of the caissons, the dimensions of and the spacing between the flanges or rings on the caissons which are engaged by corresponding ribbed or flanged faces on the locking and lifting jaws, it is diificult and often a matter of guesswork to so position the locking and gripping jaws with respect to the rings on the caissons as to insure a perfect registry therewith. Consequently, when the jaws are applied to the caissons without proper registration between the complementary rings on the caissons and the grooves in the jaws there results a slipping of the jaws upon the caissons as the weight of the barge is applied thereto which imposes undesirable and often dangerous shocks and jars to th mechanism and to the barge structure.

It is therefore the primary purpose of this invention to provide a signal attachment which shall be operatively associated with each caisson and the associated upper and lower sets of locking and lifting jaws of the hydraulic jack assembly there-for whereby the operator who may be remotely positioned upon the barge will be instantaneously and visually informed when proper registration between each of the sets of jaws and the ca-issons has been made and thereby insure eifective gripping engagement of the jaws upon the caissons and a smooth, vibrationless and silent operation of the jacks.

A further object of the invention is to provide an attachment in accordance with the foregoing object which may be conveniently and compactly housed and mounted in the framework unit which surrounds each caisson and thus form a part of the unitary assembly which each framework constitutes.

A still further object of the invention is to provide an attachment which may be readily and quickly applied to the hydraulic jack mechanism and which may be easily and accurately adjusted in order to secure an accurate indication as to the position of the vertically spaced annular supponting rings of the caisson relative to the associated jaw structure.

Still another object of the invention is to provide an indicating or signaling attachment which will afford an accurate indication as to the direction in which the jaw must move to obtain a perfect registration and engage- 3,109,289 Patented Nov. 5, 1963 ment with the mating cooperating surfaces of the carssons.

Yet another object of the invention is to provide a device in accordance with the preceding objects which shall have a simple and improved mounting means enabling easy attachment to and operative engagement with the associated structures of the caiss-ons .and jaws and wherein adjustment of the mechanism to compensate for wear developing in the associated mechanism and structure may be conveniently and easily efiected.

An additional object of the invention is to provide a signaling attachment corresponding to the foregoing objects wherein a unitary assembly of the gauging component of the device shall be compactly mounted upon a single flat panel; and whereby the means supporting this panel shall also resiliently urge it into operative gauging position relative to the corresponding caisson.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fiully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a side elevational view of an offshore drilling barge of the type disclosed in my prior applications and upon which is mounted a drilling rig, the barge being shown supported by a plurality of depending vertically adjustable caissons, the floating position of the barge being shown in dotted lines therein, in which position the caissons will be elevated with respect to the barge, and showing in full lines therein the position of the barge with the caissons lowered into barge supporting position;

FIGURE 2 is a vertical elevational view with a portion of the barge being broken away and showing in section one of the framework units which surrounds a caisson and which carries upper and lower support platforms mounting the locking jaws and the movable jaws of the hydraulic jack respectively and with the signaling attachment of this invention applied to each platform;

FIGURE 3 is a horizontal sectional view, taken substantially upon the plane indicated by the section line 33 of FIGURE 2, parts being broken away and shown in section, through the upper platform and the stationary jaw assembly and showing the jaw assembly to which the attachment is applied;

FIGURE 4 is a vertical sectional view taken upon an enlarged scale substantially upon the plane indicated by the section line 4--4 of FIGURE 2 and showing the structure of the gauging component of the attachment and its association with a caisson, certain concealed parts being shown in dotted lines and the connection of the gauging component with the signaling means being shown diagrammatically;

FIGURE 5 is an end elevational view taken from the left end oi the attachment of FIGURE 4; and

FIGURE 6 is a diagrammatic view illustrating the precise association of the upper and lower jaw assemblies and the gauging components of the invention mounted thereon and illustrating the association of these elements with a caisson structure.

FIGURE 1 discloses generally the offshore drilling barge assembly, the details of which have been set forth and claimed in my above-identified co-pending continuation-in-part application, and to which the signal attachment of the present invention is specifically adapted for use.

In FIGURE 1, the numeral Iii designates generally the barge itself upon which is mounted a drilling rig 11 over a drilling slot in the barge, not shown, in accordance with conventional practice. The barge is provided with vertically extending wells through its hull at appro riate positions over its area, not shown, and a caisson 12 is associated with each of these wells and is vertically adjustable therethrough and with respect to the barge in order to selectively and adjustably extend and retract the caissons relative to the underside of the barge to thereby enable the barge to float upon the water with the caissons in an elevated or retracted position, in the position shown in dotted lines at 14, or in the extended position of the caissons as. shown in full lines in FIGURE 1 in order to lift the barge above the surface of the water at 16 whereby the barge will constitute a stable platform for drilling operations which is elevated above and out of contact with. the water and thus will not be subject to the damaging effects of heavy waves and the like.

Each of the wells through the barge, not shown, has a framework unit 18 which surrounds the caisson 12 extending through that well, this framework unit being of the construction described in detail in my above-mentioned co-pendingcontinuationdn-part application. It will be understood that there is provided one such framework unit 18 for each of the caissons 12 and that each framework unit is rigidly secured to the hull of the barge and serves to house and contain therein as a unitary assembly therewith the jack means by which the caissons are raised and lowered and the means by which the cais sons, are locked in their vertically adjusted position with respect to the barge. Referring now to FIGURE 2 it will be observed that a portion of the barge. it) through which a caisson 12 extends is provided with an opening 20 forming a part of the barge well, not shown. Each framework unit 18 is fixedly secured to the structure of the barge and rises therefrom above the well and surrounds the caisson with the latter being vertically movable through the framework.

As in my above-mentioned prior co-pending continuation-in-part application, each framework unit 18 includes as components thereof a lower stationary platform 22 by which the framework unit is fixedly secured to the deck of the barge. 10, an upper and stationary platform 24 together with upper and lower intermediate platforms as at 26 and 28. These platforms are suitably rigidly braced to form a securely braced, sturdy and protective open framework housing for the portion of the caisson which extends therethrough and for the mechanism which is operatively associated with the caisson.

Referring next to FIGURE '2 in conjunction with FIG- URES 4 and 6 it will be observed that each of the caissons 12 comprises preferably a cylindrical or tubular pipe or column which has secured upon its exterior surface a plurality of vertically spaced circumferentially extending rings or ribs 30 which are fixedly connected thereto as by welding 32. As shown, the rings or bands 30 may extend peripherally entirely about the circumference of the caisson, although in some instances it may be preferred to form them of arcuate extent and of less circumferential extent than the entire periphery of the caisson. The bands 30 comprise and are referred to hereinafter as supporting ribs since they are operatively engaged by the power operated lifting means utilized to lift the barge upon the caissons.

By way of example, an actual construction of barge in accordance with this invention and that of my prior copending continuation-impart application includes caissons of over 200' feet in length, 6 feet in diameter and withannular ribs 8 inches in height and'spaced vertically 10 inches apart.

Disposed within each framework unit '18 is a lifting means in the form of a plurality of hydraulically operated cylinder and piston units each indicatedby the numeral 34 and which are pivotally connected at their lower ends to the, lower platform 22 as by the pivoted joints 36, and

which are provided withvertically extending piston rods 3%, the latter extending upwardly through the successive platforms and having their upper ends slidably and guidably received in guide sleeves 40 which are secured to one a or both of the platforms 24 and 26. Thus, the upper ends of the piston rods are guide-d whereby any side thrust of the piston rods is carried by the frame assembly of the framework unit 18 through the stationary platforms 24 and 26.

intermediate their ends, the set of piston rods of the power. units 34 have secured thereto and carried thereby a movable platform 42 which includes a pair of upper and lower horizontally extending plates 44 and 46. Carried and guided by and disposed between these plates is a set of lifting jaws which are adapted to releasably' and embracingly engage the caisson 12 whereby to effect relative upward and downward vertical movement of the caisson with respect to the barge and thereby raise or lower the barge as will be understood from FIGURE 1. Insofar as the invention disclosed and claimed herein is concerned, the upwardly extending andguided portions of the rods 38 and their guided engagement in the platforms 24 and 26 are immaterial and may be omitted.

The means for directing and controlling the flow of operating pressure fluid to the units .34 is of conventional design and since the principles of the invention claimed herein are not limited to any particular construction thereof, a further description of the same is deemed to be unnecessary for the purposes of this invention.

Disposed between the upper pair of stationary plat-.

which the caisson and the barge are secured or locked in vertically adjusted position.

Reference is now made to FiGURE 3 for an understanding of the construction, mounting and operation of both the upper set of locking jaws which are stationarily carried by the framework unit 18 and the lower set of lifting jaws which are movably carried by the platform 42 of the piston rods 38. Since the construction of both sets of jaws is identical, a clear understanding of the same will be understood from FIGURE 3 which shows the, arrangement of the upper set of locking jaws.

Secured to either or both of the upper and lower horizontal plates 50 and 52 are a pair of guides 54' between which are slidably mounted and guided for rectilinear horizontal travel a pair of hollow jaws 56 and 58. The two jaws are mounted for sliding movement towards and from each other between the guides, it being understood that the top and bottom surfaces of the jaws. slidably engage and are retained between the plates 56* and '52.

The adjacent faces of the jaws are closed, being provided with semi-cylindrical recesses '65) which when the jaws move towards each other are adapted to clamp and embrace the caisson 12 therebctween. dricalclamping surfaces of the jaws are provided with vertically spaced arcuate recesses 31, see FIGURE 6, which are complementary to the supporting ribs 30 for receiving thesame therein. Any desired number of these recesses 31 may be provided but it will be understood that they are spaced vertically from each other the same distance as the ribs of the caisson, or an integer multiple thereof in order to snugly embrace andclamp the latter therebetween.

As set forth in detail and claimed in my above-identified co-pending continuation-impart application, an actuating means. is housed within the hollow jaws for effecting controlled movement of the latter towards and from each other whereby to selectively cause the jaws to clamp and engage, upon the caisson with the ribs 3%) of the cais son being received in the recesses 31 of the jaws; or to open the jaws as. shown in FIGURE 3 to permit the.

The semi-cylinrecesses and ribs to clear whereby the caisson may be raised or lowered relative to the framework unit 13 and thus to the barge. It may be noted, however, that the operating means for the jaws may consist of an electric motor 64 which may be mounted upon the horizontal plate 52 and which drives a hydraulic pump 66 which through suitable control means, not shown, supplies pressure fluid to a cylinder and piston actuating unit as at 68 within one of the hollow jaws 56, and through a suitable linkage system 70 connected at opposite sides of the jaws causes simultaneous movement of the jaws towards and from each other. Stop means 72 and 73 are provided to limit movement of the jaws away from each other.

It will be understood that the same arrangement shown in FIGURE 3 in connection with the vertically stationary locking jaws 56, 58, is applied to the set of lifting jaws, not shown, which are carried by the vertically movable platform 42.

As so far described, and as set forth in detail in my above-identified application, it will be apparent that when it is desired to lift the barge upon the caissons after the barge has been moved to a suitable position for operating thedrilling rig 11, the operating means for the stationary jaws will be adjusted to release the locking jaws and expand the same into their non-engaged position as shown in FIGURE 3 and in FIGURE 6. Thereupon the operating means of the lifting jaws of the platform eZ'will be actuated to cause the lifting jaws to moveinward from their open position of FIGURE 6 and to clamp upon the ing or upper set of stationary jaws are then actuated to securely grip the caissons and lock them in thisposition, whereupon the lifting jaws are released from the caisson, and the lifting means 34 are returned to their upper position for effecting a new engagement of the lifting jaws upon the caisson. This operation is repeated until the barge has been lifted the desired distance above the water. A reverse operation is effected when'it is desired to lower the barge and retract the caissons when it is intended to move the barge to a new location.

In the interest of safety, after the barge has been elevated to a desired position, both the lifting jaws and the locking jaws may be clamped upon the caisson thus effecting a double supporting action for the latter. In general, however, it would be preferred to allow the locking jaws the raised portions of the jaws between successive recesses slide off of the surface of the ribs. Obviously the abrupt jar and shock which occurs when the barge thus drops from one rib to the adjacent rib is considerable, and is liable to result in damage to the caisson and rib structure, to the jaw assemblies, to the lifting means if it should be the lifting jaws which slip, and to the barge structure and the mechanism carried thereby. Even if this slippage should be only the distance from one rib to the next, it is extremely undesirable and dangerous; while if it should continue for more than one rib, it could well be attended by serious consequences. The mechanism to be now set forth and which forms the subject matter of the invention to transmit the entire weight of the barge through the unitslS to the caissons, thereby relieving the lifting mechanism of this load.

Since it may be necessary to lift the barge for a considerable distance along the caissons, as for example when the barge is lifted thirty-five or forty feet above the'water level 16, there is usually a substantial distance in the order of 10 inches between successive, supporting ribs 36 on the caissons. This requires a corresponding spacing between the complementary recesses 31' of the sets of locking and lifting jaws. Owing to the dimensions of the parts involved, it is therefore frequently difficult and usually impossible in view of the concealed position of the jaws and their recesses with respect to the ribs of the caissons, to directly ascertain when the recesses 31 of the jaws are in registration with the corresponding ribs 30. If the recesses are not in complete registration with the ribs, then the ribs will engage the raised surfaces of the jaws on either side of the recesses whereby an imperfect gripping engagement of the caisson is etfected. When this occurs, it is possible when the weight of the barge is applied to the locking jaw assembly as by releasing the engagement of the lifting jaws with the caisson, for the barge to slip downwardly upon the caisson until claimed herein is intended to overcome this difficulty by affording a signal which will correctly indicate the relative position of the ribs with the recesses and thus clearly show when they are in registration for interlocking engagement. This signaling means is in the form of an attachment to the hydraulic jack or lifting means herein'oefore described, and may be installed either initially when the barge is built and as a component of the framework unit 18, or may be applied at any time thereafter when its services are desired.

Since the signaling attachment is identical for use with both the set of locking jaws and the set of lifting jaws, a description of the construction and operation of the sig naling attachment as shown in FIGURES 4 and 5 will now be set forth.

In applying the signaling system of this invention to a barge, there are employed two of the signaling attachments to each caisson of which one attachment cooperates with the upper or stationary locking jaw assembly while the other cooperates with the lower or movable lifting jaw assembly.

Each signaling attachment includes a detector means or gauging component orunit and a remotely located indicating or signaling component. The gauging unit is a unitary assembly all of whose elements are mounted upon a base 84) in the form of a fiat panel or plate which is positioned with one vertical edge in proximity to and in side-by-side relation to a caisson. The panel is supported for both vertical adjustment and for lateral swinging movement towards and from the caisson by means of a pair of transversely extending straps 82 embracing the panel at its upper end and upon opposite surfaces thereof. Each strap has a pair of longitudinally spaced, laterally projecting apertured lugs 83 through which are received fastening bolts 85 adjustably engaging apertured ears 87 welded or otherwise secured to the panel it for supporting the latter in vertically adjustable positions from the straps 82.

The straps 82 in turn are swingably carried from a mounting bracket 38 which is welded or otherwise r igidly secured to a frame member 99 forming a part of the upper stationary platform 24 or depending from the un- Iderside :of the movable platform 42 as suggested best in FIGURE 6.

Two pairs of support links 92 embrace the bracket 88 and the straps 82 of the base plate '80, being pivoted to the former at'94 and to the straps and plate by bolts 96. It will be observed that the bolts 96 directly connect the straps to the bracket and are slidably received in vertical slots 84 and 86 provided in the plate 80'. Thus, the

straps can freely swing from the bracket 88 for pivotal movement upon radii of constant length; while by sliding of the bolts 96 in the slots 84, vertical adjustment of the panel 80 is. effected through the mounting means '83, 85 and 87.

The panel or base 80 is yieldlingly urged toward the caisson as by means of a mounting bracket 98 carried by a frame member which may form a part of either the lower partition 52 associated with the support for the locking jaws or the lower partition 4-6 associated with the platform 42 upon which is mounted the setof lifting jaws. A spring 102 is secured to the bracket 98 rib. The signal device may be in the form of an elec- In some in tric light, an electric bell or other means. stances, the devices 104 and 106 may be associated or interconnected with the control means of the associated set of jaws whereby to prevent operation of the latter when the jaws are not in proper registration with the ribs on the caisson;

Each of the signal means 104 and 106 is provided with a connecting means by which it is connected to and operated by a corresponding detector device carried by the base 80 and to be now described.

Considering specifically the lowermost detector device and signaling system, it will be seen that the base plate 80 is provided with a vertically elongated slot 108. A movable element 110 in the form of a lever is vertically adjustably and pivotally mounted in the slot 108 as by a pivot means 112. At its lower end the movable element 110 is provided with a feeler in the form of a roller 114' journaled thereon and which roller is adapted to slide upon the adjacent surface of the caisson as relatively movement between the gauging unit and the caisson occurs. Inter-mediate its ends, the movable element 110* is pivotally connected at 116 to one end of a connecting link 118 whose other extremity is adjustably connected as by a fastener 120 to a selected one of a series of longitudinally spaced bores in the mid portion of a lever 122. The latter is pivoted at 124 to the base plate 80 and a resilient means 126 is anchored at one end at 128 to the base plate and at its other end is secured to the lever 122 and yieldingly urges the lever 122, the link 118 and the member 110 towards the caisson.

At its lower end, the lever 122 is connected by a link 130 to the actuating member of a switch 132 which latter controls an electrical circuit consisting of the conductors 134 which circuit is connected to the signal device 106.

Upon the other face of the base 80 there is provided an identical detector device but whichris positioned vertically above the detector device just described whereby its feeler element .114 will engage the upper edge of a rib 30 |which is preferably the same ribas that engaged by the lower detector device and at the same time as the feeler element of the lower detector device engages the lower edge of a rib. The operation of this second signaling system is identical to that previously described except that it detects and responds to the position of the upper edge of a rib, while the lower system cooperates with the lower edge of the rib.

By this means, when the caisson is vertically elevated so that its ribs are in approximate registration with the complementary recesses of the associated set of jaws, the vertical elevation of a rib with respect to the jaws will be indicated lby the two signals 104 and 106 as the upper and lower detector devices feel and respond to the position of the upper and lower edges of the rib.

, mentioned advantages.

7 For a clearer understanding of the specific structure and arrangement of the gauging component relative to a 8 caisson, attention is now directed to the somewhat diagrammatic showing of FIGURE 6. As previously mentioned, an actual construction to which this invention has been applied includes ribs 30 which are 10 inches apart and are 8 inches wide. The cooperating jaws 56, 58 of both the lifting and the locking sets of jaws are so dimensioned that when the horizontal center line 140 of their recesses 31 are in horizontal alignment with the horizontal center line of the corresponding rib 30,. as illustrated in FIGURES 6, there will be a uniform vertical clearance shown at 142 and 144 respectively between the top and bottom surfaces 146 and 140 of the jaws and the adjacent overlying and underlying surfaces 150 and 152 of adjacent ribs 30. r

Each of the clearances .142 and 144- is about A of an inch thereby enabling easy engagement of the jaws with the caisson. v 1

The operation of the signaling device and the cooperation of the gauging unit thereof with a caisson is as follows. Starting first with both sets of jaws in clamping engagement with the ribs of a caisson, both of the rollers 114 or the upper and lower detector devices will ride upon the smooth cylindrical outer surface of one of the ribs 30. This is made possible by spacing the rollers by a distance just slightly less than 8 inches which is the width of a rib. At this time the levers 110 and the associated linkages will cause actuation of both signaldevices 10 4, 106 showing that the corresponding jaw is in perfect registry with the adjacent rib 30 and therefore that the jaw is either properly locked to the caisson or else is in proper registry for movement into or out of locking engagement.

As relative vertical movement son and the jaw assembly, the roller 114 of one ofthe detector devices, depending upon the direction of 'movement, will drop oil of the edge of the flat surface of I the rib 30 and into the adjacent annular channel, al-

lowing the cor-responding sign-a1 light 104 or 106 to go out or change. Since the annular space between the ribs is considerably wider than the ribs themselves, both detector devices will deactivate both signal devices when the rollers pass from one rib to another. Thus with both signal lights off, the operator knows that'the jaws are substantially midway between two adjacent ribs.

As the relative vertical movement between caisson and .jaw assembly continues, the roller 114 which firstleft therouter surface of a rib and thereby-deactivated its signal will be the first to engage the next rib and therefore re-activate its signal. When this signal is given, the operator will be informed that the jaws are now approaching registry with the next rib.

After the other detector device has activated its signal and with the first signal still being emitted the operator will be aware that proper registration of jaw assembly and rib has been attained and that the jaw assembly may now be actuated to gripping position.

It will be apparent that the use of the upper and lower detector devices will at once indicate which direction of travel is necessary to secure perfect registry of the caisson and jaws. Thus with one. signal showing and the other signal off, it is at once apparent that caisson must Owing to the small tolerance provided, guesswork as to the condition of registry'of the ribs and jaws and uncertainty as to the direction of movement required for registry is completely eliminated.

In the attached drawings and in the accompanying description there has been set forth an arrangement where occurs between the cais-- in the upper and lower detector devices are positioned for actuation by the upper and lower edges of the same rib. However, since the rib spacings upon the caisson and the rib widths are necessarily uniform, it is also within the scope of this invention to position the upper and lower detector devices to engage the top and bottom rib edges respectively of adjacent or different ribs as may be found convenient; and the rib whose registry with the set of jaws is to be indicated may comprise one of these two different ribs or even still another rib. This feature of the invention greatly increases the ability to locate the gauging unit of the signaling device at any one of numerous locations as may be found to be most convenient.

Hereinbefore, reference has been made to a hydraulic actuating means for the clutch jaws, this being the mechanism disclosed in my above mentioned application. However, other suitable actuating means such as an electric motor connected to the jaws to open and close them may also be provided.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In an offshore drilling barge having vertically movable supporting caissons mounted thereon, the combination of each caisson with a jack mechanism including, a

framework fixedly mounted on said barge and surrounding the associated caisson, each caisson having vertically spaced circumferentially extending supporting ribs thereon, with the distance between adjacent ribs being greater than the width of said ribs, said jack mechanism comprising a set of locking jaws mounted on said framework and restrained against vertical movement and having complementary recesses for grippingly engaging said ribs therein for locking said barge and caisson in vertically adjusted position, a set of lifting jaws disposed in said framework for vertical movement therein and having complementary recesses for grippingly engaging said ribs therein for relative vertical movement of said barge and caisson, power operated lifting means carrying said set of lifting jaws for vertical movement of the latter, a signaling attachment comprising at least one detector device mounted in said framework in operative relation to one of said sets of jaws, said device including a movable element positioned for continuous longitudinal sliding engagement with the exterior surface of a caisson and movable therealong and adapted to be actuated by its passage over a supporting rib, a signal device, means connecting said detector device to said signal devicefor operation of the latter upon actuation of the former, said detector devicebeing correlated with the positions of said supporting ribs and said complementary recesses whereby actuation of said detector device and the operation of said signal device will be synchronized with registration of said recesses and ribs with said jaws.

2. The combination of claim 1 including means supporting said detector device in fixed relation to said set of locking jaws.

3. The combination of claim 1 including means supporting said detector device in fixed relation to said set of lifting jaws and movable therewith.

4. The combination of claim 1 including'a detector device, signal device and connecting means for each set of jaws. V

5. The combination of claim 1 wherein said signaling attachment includes a base, said movable element being movably mounted upon said base for movement towards and from the associated caisson.

6. The combination of claim 1 wherein said'signaling 10 attachment includes a base, said movable element being movably mounted upon said base for movement towards and from the associated caisson, means for adjusting the mounting of said movable element upon said base for varying the relation of its engagement with a rib to the registration of said ribs'and recesses.

7. The combination of claim 1 including adjustable mounting means supporting said base for vertical adjust ment relative to said caisson and for movement towards and from said caisson.

8. The combination of claim 1 wherein said signaling attachment includes pairs of movable elements and signal devices with each of the former connected to one of the latter, said movable elements being positioned such that they will engage the opposite vertically spaced horizontal edges of a rib whereby to indicate the relative position of said recesses to said ribs.

9. The combination of claim 6 including resilient means connected to said movable element for yieldingly urging the latter into contact with said caisson.

10. The combination of claim 9 wherein said connect ing means comprises an electric circuit operatively connected to said signal device, a switch controlling said circuit, said movable element being connected to said switch.

11. The combination of claim 7 including a spring engaging said base and yieldingly urging the latter towards said caisson.

12. The combination of claim 8 wherein said signaling attachment includes a base, said movable elements being mounted on opposite sides of said base.

13. The combination of claim 12 wherein said movable elements are disposed in vertically spaced relation to each other for engaging respectively the vertically spaced horizontal top and bottom surfaces of a rib.

14. In combination, a generally horizontal platform, a caisson extending through said platform for generally vertical sliding movement relative thereto, a series of longitudinally spaced circumferential rings comprising radial ribs upon the exterior of said caisson, the width of said ribs being less than the space between adjacent ribs, a pair of jaws mounted upon said platform for movement relative to each other and towards and from said caisson, recesses on said jaws complemented to and receiving therein said ribs when the latter are alined with said recesses, a signaling attachment for indicating the registering of said ribs and recesses, said signaling attachment comprising a detector means disposed in operative rela tion to said caisson and a signal device together with means connecting said detector means with said signal device for operation of the latter upon actuation of the former, said detector means comprising a pair of movable elements each connected to said connecting means, said moving elements having contact portions spaced from each other longitudinally of said caisson such that the contact portions may simultaneously engage the longitudinally spaced top and bottom edges of ribs, means yieldingly urging each contact portion with continuous contact with the surface of a caisson during relative movement of the latter, said connecting means and signal devices indicating when each contact portion is in engagement with a rib.

1 l ment towards and from said caisson, means resiliently urging said base towards said caisson.

18. The combination of claim 14 wherein said detector means includes a base upon which said movable elements are mounted, adjustable mounting means supporting said base in longitudinally adjustable position relative to said caisson for varying the synchronization of said movable elements relative to said ribs, means mounting said movable elements upon said base in relatively adjusted positions upon said base.

.19. The combination of claim 14 including a support base upon which said movable elements are mounted, an

actuating lever pivotally mounted upon said plate for each 7 of said elements, means operatively connecting said actu- 20. The combination of claim 19 wherein said movable elements and their associated levers and connectingmem bers are mounted upon opposite sides of said plate.

21. The combination of claim 20 wherein said plate has an adjusting slot therein, an adjustable support secured to one of said movable elements and slidably secured in said slot for adjustably spacing said elements from each other longitudinally of said caisson.

' References Cited in the file of this patent UNITED STATES PATENTS 1,780,568 Scarpa Nov. 4, 1930 1,966,249 Larson July 10, 1934 2,932,486 Suderow Apr. 12, 1960 2,954,676 Guy et al Oct. 4, 1960 2,975,560 Leonard Mar. 21, 1961 

1. IN AN OFFSHORE DRILLING BARGE HAVING VERTICALLY MOVABLE SUPPORTING CAISSONS MOUNTED THEREON, THE COMBINATION OF EACH CAISSON WITH A JACK MECHANISM INCLUDING, A FRAMEWORK FIXEDLY MOUNTED ON SAID BARGE AND SURROUNDING THE ASSOCIATED CAISSON, EACH CAISSON HAVING VERTICALLY SPACED CIRCUMFERENTIALLY EXTENDING SUPPORTING RIBS THEREON, WITH THE DISTANCE BETWEEN ADJACENT RIBS BEING GREATER THAN THE WIDTH OF SAID RIBS, SAID JACK MECHANISM COMPRISING A SET OF LOCKING JAWS MOUNTED ON SAID FRAMEWORK AND RESTRAINED AGAINST VERTICAL MOVEMENT AND HAVING COMPLEMENTARY RECESSES FOR GRIPPINGLY ENGAGING SAID RIBS THEREIN FOR LOCKING SAID BARGE AND CAISSON IN VERTICALLY ADJUSTED POSITION, A SET OF LIFTING JAWS DISPOSED IN SAID FRAMEWORK FOR VERTICAL MOVEMENT THEREIN AND HAVING COMPLEMENTARY RECESSES FOR GRIPPINGLY ENGAGING SAID RIBS THEREIN FOR RELATIVE VERTICAL MOVEMENT OF SAID BARGE AND CAISSON, POWER OPERATED LIFTING MEANS CARRYING SAID SET OF LIFTING JAWS FOR VERTICAL MOVEMENT OF THE LATTER, A SIGNALING ATTACHMENT COMPRISING AT LEAST ONE DETECTOR DEVICE MOUNTED IN SAID FRAMEWORK IN OPERATIVE RELATION TO ONE OF SAID SETS OF JAWS, SAID DEVICE INCLUDING A MOVABLE ELEMENT POSITIONED FOR CONTINUOUS LONGITUDINAL SLIDING EN- 